A cart would no doubt be better (as long as the trail is wide enough), but all of the photos I saw from the war were simple bikes with huge loads, being walked by a person with both hands on the handlebars and both feet on the ground. Seems to me that a heavily loaded bike is going to fall over a lot, not to mention having to "drop" your bike to help a buddy over a log, etc.

I used to fish a little walk in lake with a friend. There was a dirt road, very steep in places, so he made a frame from an old bedframe, and put two bike wheels on the sides. We would set his flat bottomed jon boat on the frame, load it with our gear, and a fishin' we would go. Only problem was coming out, on the steep part of the road it seemed that we pushed up one step and slid back two. Probably still better than carrying the thing tho...